Cache the return values of getBlendOpts in GrDrawState

src/gpu/GrDrawState.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrDrawState.h"
 #include "GrPaint.h"
 
@@ skipping 41 matching lines @@
 
     // Enable the clip bit
     this->enableState(GrDrawState::kClip_StateBit);
 
     this->setColor(paint.getColor());
     this->setState(GrDrawState::kDither_StateBit, paint.isDither());
     this->setState(GrDrawState::kHWAntialias_StateBit, paint.isAntiAlias());
 
     this->setBlendFunc(paint.getSrcBlendCoeff(), paint.getDstBlendCoeff());
     this->setCoverage(paint.getCoverage());
+    fBlendOptFlags = kInvalid_BlendOptFlag;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 
 static size_t vertex_size(const GrVertexAttrib* attribs, int count) {
     // this works as long as we're 4 byte-aligned
 #ifdef SK_DEBUG
     uint32_t overlapCheck = 0;
 #endif
     SkASSERT(count <= GrDrawState::kMaxVertexAttribCnt);
@@ skipping 40 matching lines @@
             fFixedFunctionVertexAttribIndices[attribs[i].fBinding] = i;
         }
 #ifdef SK_DEBUG
         size_t dwordCount = GrVertexAttribTypeSize(attribs[i].fType) >> 2;
         uint32_t mask = (1 << dwordCount)-1;
         size_t offsetShift = attribs[i].fOffset >> 2;
         SkASSERT(!(overlapCheck & (mask << offsetShift)));
         overlapCheck |= (mask << offsetShift);
 #endif
     }
+    fBlendOptFlags = kInvalid_BlendOptFlag;
     // Positions must be specified.
     SkASSERT(-1 != fFixedFunctionVertexAttribIndices[kPosition_GrVertexAttribBinding]);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 
 void GrDrawState::setDefaultVertexAttribs() {
     static const GrVertexAttrib kPositionAttrib =
         {kVec2f_GrVertexAttribType, 0, kPosition_GrVertexAttribBinding};
 
     fVAPtr = &kPositionAttrib;
     fVACount = 1;
 
     // set all the fixed function indices to -1 except position.
     memset(fFixedFunctionVertexAttribIndices,
            0xff,
            sizeof(fFixedFunctionVertexAttribIndices));
     fFixedFunctionVertexAttribIndices[kPosition_GrVertexAttribBinding] = 0;
+    fBlendOptFlags = kInvalid_BlendOptFlag;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 
 bool GrDrawState::validateVertexAttribs() const {
     // check consistency of effects and attributes
     GrSLType slTypes[kMaxVertexAttribCnt];
     for (int i = 0; i < kMaxVertexAttribCnt; ++i) {
         slTypes[i] = static_cast<GrSLType>(-1);
     }
@@ skipping 129 matching lines @@
      */
     return kOne_GrBlendCoeff == fDstBlend ||
            kISA_GrBlendCoeff == fDstBlend ||
            kISC_GrBlendCoeff == fDstBlend ||
            this->isCoverageDrawing();
 }
 
 GrDrawState::BlendOptFlags GrDrawState::getBlendOpts(bool forceCoverage,
                                                      GrBlendCoeff* srcCoeff,
                                                      GrBlendCoeff* dstCoeff) const {
+    GrBlendCoeff bogusSrcCoeff, bogusDstCoeff;
+    if (NULL == srcCoeff) {
+        srcCoeff = &bogusSrcCoeff;
+    }
+
+    if (NULL == dstCoeff) {
+        dstCoeff = &bogusDstCoeff;
+    }
+
+    if (0 == (fBlendOptFlags & kInvalid_BlendOptFlag)) {
+        *srcCoeff = fOptSrcBlend;
+        *dstCoeff = fOptDstBlend;
+        return fBlendOptFlags;
+    }
+
+    fBlendOptFlags = this->calcBlendOpts(forceCoverage, srcCoeff, dstCoeff);
+    fOptSrcBlend = *srcCoeff;
+    fOptDstBlend = *dstCoeff;
+
+    return fBlendOptFlags;
+}
+
+GrDrawState::BlendOptFlags GrDrawState::calcBlendOpts(bool forceCoverage,
+                                                      GrBlendCoeff* srcCoeff,
+                                                      GrBlendCoeff* dstCoeff) const {
 
     GrBlendCoeff bogusSrcCoeff, bogusDstCoeff;
     if (NULL == srcCoeff) {
         srcCoeff = &bogusSrcCoeff;

[bsalomon, 2014/07/17 18:41:03]

Seems like we don't need this anymore. Also if none of the callers pass NULL for
srcCoeff or dstCoeff we could probably just require the params to be non-NULL
and do away with this entirely.

[egdaniel, 2014/07/17 19:35:50]

I've actually already removed this in a follow up patch for the cl, but I want
to keep the ability to pass in NULL for src and dst since I will be using this
for some of my follow up cl's where all I care about is the blend flags.

     }
     *srcCoeff = this->getSrcBlendCoeff();
 
     if (NULL == dstCoeff) {
         dstCoeff = &bogusDstCoeff;
     }
     *dstCoeff = this->getDstBlendCoeff();
 
+
     if (this->isColorWriteDisabled()) {
         *srcCoeff = kZero_GrBlendCoeff;
         *dstCoeff = kOne_GrBlendCoeff;
     }
 
     bool srcAIsOne = this->srcAlphaWillBeOne();
     bool dstCoeffIsOne = kOne_GrBlendCoeff == *dstCoeff ||
                          (kSA_GrBlendCoeff == *dstCoeff && srcAIsOne);
     bool dstCoeffIsZero = kZero_GrBlendCoeff == *dstCoeff ||
                          (kISA_GrBlendCoeff == *dstCoeff && srcAIsOne);
@@ skipping 155 matching lines @@
         fDrawState->fColorStages[s].saveCoordChange(&fSavedCoordChanges[i]);
         fDrawState->fColorStages[s].localCoordChange(coordChangeMatrix);
     }
 
     int numCoverageStages = fDrawState->numCoverageStages();
     for (int s = 0; s < numCoverageStages; ++s, ++i) {
         fDrawState->fCoverageStages[s].saveCoordChange(&fSavedCoordChanges[i]);
         fDrawState->fCoverageStages[s].localCoordChange(coordChangeMatrix);
     }
 }